Growth Curves, Measurement and Three-Dimensional Reconstruction in the Histopathology of Temporal Bones

Abstract

The paper consists of three parts, in which the opportunities for measurement in histopathology of the temporal bone are shown. Measurement of size and distance (1D measurement) is used for determining the growth curves during the fetal period. Measurement of area (2D measurement) shows a difference in volume of mesenchymal tissue in the middle ear cavity between the groups with and without kidney pathology during the prenatal period. A computer 3D reconstruction of malformations of the middle and inner ears can be applied in understanding the pathology of the hearing organ. The first part concerns the application of measurements of size and distance to a set of 121 temporal bones from 71 fetuses. For evaluation, the following parameters were collected from the histological samples: the height and width of the stapes, the height of the vestibule, the length of the macula sacculi, the length of the macula utriculi, and the height and width of the cochlea. Regression analysis was applied to the data set to determine the relationship of the growth curves of particular structures. The data for growth curves from 36 aborted, presumably normal fetuses, are used. So the growth curves show the normal development of these structures. The Mitscherlich model was found to be the most satisfying for the growth curve in the fetal period. The amount of mesenchymal tissue in the middle ear (2D measurement) was determined after computer digitalization (Lucia) of the samples’ area of the middle ear cavity. Statistical tests confirmed a larger amount of this tissue in the group of samples obtained from fetuses with pathological kidney findings (agenesis of kidneys, Potter’s sequence), in comparison with a group of spontaneously aborted fetuses without kidney damage.The 3D computer reconstruction of the temporal bone, the third topic, was created using our own Medicus software written for the project. In a sample of bone without pathology, reconstruction enabled assessment of basic anatomical structures and two temporal bones show malformation of the stapes (VATER syndrome) and the cochlea (trisomy 21).